Apparatus for controlling the operating mixture composition in internal combustion engines

摘要

An apparatus is proposed for controlling the composition of the operating mixture in internal combustion engines. In this apparatus, a control of the air quantity is effected in accordance with the arbitrarily adjustable fuel quantity by throttling the air intake cross section and by remnant filling of the combustion chambers of the engine by means of recirculated exhaust gas. On the basis of the comparison of the aspirated air quantity with the injected fuel quantity by means of a differential pressure valve, a control pressure building up at a fixed throttle in a discharge line controlled by the differential pressure valve is generated as a control variable for an actuation device of the air throttle valve or for the exhaust recirculation valve in an exhaust recirculation line. On cold starting and warm-up of the engine, a substantially larger fuel quantity is simulated by the diversion of a portion of the compared fuel quantity, and thus a high control pressure is very rapidly attained, with the aid of which the fuel intake cross section is fully opened and the cross section of the exhaust recirculation line is completely closed. This diversion of the fuel is also effected, for instance at full load, whenever the intention is reliable prevention of exhaust recirculation.